Not exactly sure what or why it happened but I came home from work one day and turned it on and was about to play some music when a puff of smoke came out of it? needless to say I took it apart a few days later and found all of the right side op's were shorted and upon further investigation a bunch of resistors were fried on the right driver f-3074 and on f-3073 I found a couple of transistors and resistors were also fried I replaced about every,transistor,resistor,trimmer and electrolytic cap on both sides f-3074,f-3073,f-3072 and put some Mj21194g,93g op's in it for now and everything is working fine again..Now I'm just waiting for the new op's to arrive..Good choice. I did the same and found that the G9700 runs cooler at higher volumes probably due to the additional headroom of the 2608/1117 pairs.
With the volume set to 4, things are earth shaking. -Again, just added headroom.
Hope all turns out ok for you.
moe of the North.
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I forgot to mention the .33k emitters on the right one was cracked in half and two were way off specs so I replaced all of them both channels.It seems odd that all the op's were toast on one side? I burned up one set right side and similiar to your situation, found misc resistors/transistors on that side had taken the hit upstream of the 2607/11116 pairs. Also found that 2 of the 33k thermos resistors had fried as well, not sure if you've replaced or checked yours 33k thermos but be suspect.
I've been playing this at low levels with the sacrificial Mj21194g,93 op's for a month or so now with zero problems accept for the first time I put them in and forgot that they were lower power and when I turned it up about half throttle it blew the whole right side(op's only)..been playing about everyday for an hour or so on half to three quarter volume with no problems ever since..It seems odd that all the op's were toast on one side? I burned up one set right side and similiar to your situation, found misc resistors/transistors on that side had taken the hit upstream of the 2607/11116 pairs. Also found that 2 of the 33k thermos resistors had fried as well, not sure if you've replaced or checked yours 33k thermos but be suspect.
MJ15003/4's are much older than MJ21193/94 series.Those MJ15003/4's have caught my eye too lately as McIntosh is quite fond of them.
However have had nothing but good luck with the 93/4's and never seen one fail.
I've been playing this at low levels with the sacrificial Mj21194g,93 op's for a month or so now with zero problems accept for the first time I put them in and forgot that they were lower power and when I turned it up about half throttle it blew the whole right side(op's only)..been playing about everyday for an hour or so on half to three quarter volume with no problems ever since..
I've been playing this at low levels with the sacrificial Mj21194g,93 op's for a month or so now with zero problems accept for the first time I put them in and forgot that they were lower power and when I turned it up about half throttle it blew the whole right side(op's only)..been playing about everyday for an hour or so on half to three quarter volume with no problems ever since..
The only board on the power supply section that I didn't touch is the RF power supply board F-3071..The bias and dc offset adjustments are right on..I checked and rechecked the adjustments and they haven't changed at all..If that's happened you have some other issue, the MJ21193/4 are most likely twice the voltage and twice the current of the original....
It plays just fine unless I turn the volume up half way with the loudness button on then it go's into protection after 30 seconds or so but with loudness button off it continues to play just fine.snip ---
The bias and dc offset adjustments are right on..I checked and rechecked the adjustments and they haven't changed at all..
If this is true then you may be fighting an oscillation issue.
If this is true then you may be fighting an oscillation issue.
Also at half volume the power meters are pegged out at 200w..It plays just fine unless I turn the volume up half way with the loudness button on then it go's into protection after 30 seconds or so but with loudness button off it continues to play just fine.
This sounds like excessive DC or a tired protection circuit problem. Most likely another and different problem than the blowing channel.It plays just fine unless I turn the volume up half way with the loudness button on then it go's into protection after 30 seconds or so but with loudness button off it continues to play just fine.
I replaced every transistor,electrolytic cap and most of the resistors in the power supply,drivers and protection circuit.I didn't replace the relays or any jfets and I didn't touch the RF power supply board..This sounds like excessive DC or a tired protection circuit problem. Most likely another and different problem than the blowing channel.
Although, half volume on this receiver is REALLY FRIKIN LOUD dude. Might not be a damn thing wrong with anything if you are over-driving it.
I like to give my stuff a stiff test once in awhileThis sounds like excessive DC or a tired protection circuit problem. Most likely another and different problem than the blowing channel.
Although, half volume on this receiver is REALLY FRIKIN LOUD dude. Might not be a damn thing wrong with anything if you are over-driving it. From what you just said, I am inclined to believe that the receiver is trying to protect itself, from you.
Curious how much power you are putting out at half volume then. Should be just about all she's got captain.I replaced every transistor,electrolytic cap and most of the resistors in the power supply,drivers and protection circuit.I didn't replace the relays or any jfets and I didn't touch the RF power supply board..
Ya I'd like to get it checked out on a scope or something to check for oscillation but nobody around here does it that I can find..Curious how much power you are putting out at half volume then. Should be just about all she's got captain.